Time frequency synchronization method for time division long-term evolution (TD-LTE) system

A technology of frequency synchronization and system time, applied to multi-frequency code systems, baseband system components, etc., can solve problems such as complex calculations and long processing times

Inactive Publication Date: 2011-07-20
CHONGQING UNIV OF POSTS & TELECOMM +1
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Problems solved by technology

[0005] The present invention aims at defects such as complicated calculation and long processing time in realizing time synchronization and fractional multiple frequency synchronization of the prior art TD-LTE system, and the present invention proposes a time synchronization and fractional multiple frequency synchronization method

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  • Time frequency synchronization method for time division long-term evolution (TD-LTE) system
  • Time frequency synchronization method for time division long-term evolution (TD-LTE) system
  • Time frequency synchronization method for time division long-term evolution (TD-LTE) system

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Embodiment Construction

[0038] The invention discloses a method for TD-LTE system time synchronization and fractional multiple frequency synchronization, according to the actual channel environment, the time synchronization point and fractional multiple frequency offset obtained respectively by using simplified ML algorithm and PSS For weighted average, refer to image 3 , including the following steps:

[0039] (101) The baseband signal received by the receiving end is down-sampled (1 / 2, 1 / 4 or 1 / 8 down-sampling can be used), that is, one symbol is sampled every 2, 4, or 8 symbols. The following takes 1 / 4 downsampling as an example for illustration. Calculation formula and the formula

[0040] exist hour, and and save the value as the recursive method to calculate the next sampling symbol The initial value of the value. in, is the sequence number in the time domain, is the length of CP, is the number of sampling points for one OFDM symbol, is the baseband digital signal after ...

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Abstract

The invention discloses a method for resolving time synchronization and decimal frequency synchronization in a time division long-term evolution (TD-LTE) system by using weighted average and relates to the technical field of mobile communication. Aiming at the synchronization problem in the TD-LTE system in the prior art, the method comprises the following steps of: delaying an orthogonal frequency division multiplexing (OFDM) symbol sampling point for a baseband digital signal which is received at a receiving end, performing normalized autocorrelation in a time domain to generate a peak value, and obtaining a time synchronization point and decimal frequency offset; performing cross-correlation on the baseband digital signal and a locally generated primary synchronization signal (PSS) in the time domain, and obtaining higher-accuracy time synchronization point and decimal frequency offset according to a peak value which is generated trough the cross-correlation; and obtaining time-domain channel estimation through the PSS signal by using non-coherent detection, performing weighted average in time synchronization and decimal frequency synchronization which are obtained in a simplified maximum likelihood (ML) algorithm and the PSS respectively according to channel impulse response length so as to adapt to environmental change of the channel and effectively acquire stable-performance time-frequency synchronization. The invention provides a method for time synchronization and decimal frequency synchronization which adapt to channel environment.

Description

technical field [0001] The present invention relates to the technical field of mobile communication, in particular to a method for time synchronization and fractional multiple frequency synchronization in the third-generation mobile communication long-term evolution system (hereinafter referred to as TD-LTE). Background technique [0002] The 3GPP (3rd Generation Partnership Project) organization started the long-term evolution of air technology in March 2005. The goal of LTE is based on OFDMA (Orthogonal Frequency Division Multiplexing Access) multiple access and multiple antennas. In the TD-LTE system, the multiple access technology in the downlink direction adopts OFDM (Orthogonal Frequency Division Multiplexing) technology, which has high spectral efficiency, high peak rate, and can well resist inter-channel Interference, frequency selective fading, and impulse noise, etc., when the terminal uses 2 antennas to receive, the instantaneous peak rate can reach 100Mbit / s (th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04L25/02
Inventor 陈发堂马磊李小文王丹王华华刘宇许彦斌凌云志黄武
Owner CHONGQING UNIV OF POSTS & TELECOMM
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